Hitherto, as a solvent for diluting silicone compounds, hydrochlorofluorocarbons (HCFCs) such as dichloropentafluoropropane (R225), 1,1-dichloro-1-fluoroethane (R141b), etc. have widely been used, since they are nonflammable and superior in chemical and thermal stabilities. Since there is also a reason that HCFCs contain chlorine, they are high in ozone depletion potential (ODP), causing concern about the effect on the global environment. Therefore, they are scheduled to be totally abolished in the future.
In recent years, as one of solvents alternative to HCFCs, the use and the development of hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs) have been in progress. HFCs and HFEs have advantages that they are nonflammable, that they are superior in chemical and thermal stabilities and drying characteristics, that they have no ozone depletion potential, etc.
HFCs and HFEs are, however, not sufficient in silicone compound solubility. Therefore, hitherto, a method of adding various organic solvents has been studied in order to improve silicone compound solubility.
For example, in order to improve compatibility between HFEs and silicone compounds, there are disclosed a method of adding 4-30 mass % of hexamethyldisiloxane (Patent Publication 1) and a method of adding 15-60 mass % of hydrocarbons, such as normal hexane, etc., and alcohols (Patent Publication 2).